Evaporation chamber for a basic oxygen furnace



H. MITCHELL ETAL 3,345,057

EVAPORATION CHAMBER FOR A BASIC OXYGEN FURNACE 5 Sheets-Sheet 1 Filed Dec. 15, 1964 FIG. 2

INVENTOR. HAETMAN M/TCHELL 6 ,POY W- WALKER fit/r EVAPORATION CHAMBER FOR A BASIC OXYGEN FURNACE I Filed Dec. 15. 1964 Oct. 3, 1967 H. MITCHELL ETAL 5 Sheets-Sheet 2 INVENTOR5 HART/MAN MITCHELL 6' RUY l4. WALKER Meir FIG. 5

Oct. 3, 1967 H. MITCHELL ETAL 3,345,057

EVAPORATION CHAMBER FOR A BASIC OXYGEN FURNACE Filed Dec. 15. 1964 3- Sheets-Sheet 5 I INVENTOR. HAETMAN MITCHELL 6 YEOY W WALKER FIG. 6

United States Patent 3,345,057 EVAPORATION CHAMBER FOR A BASIC OXYGEN FURNACE Hartman Mitchell and Roy W. Walker, Pittsburgh, Pa., assignors to Koppers Company, Inc., a corporation of Delaware Filed Dec. 15, 1964, Ser. No. 418,456 9 Claims. (Cl. 266-35) ABSTRACT OF THE DISCLOSURE An evaporation chamber for use with a basic oxygen furnace and hood that has a vertical tubular, fluid-conductive frame structure and a plurality of panels disposed between and connected to the frame structure to form the effluent retaining walls of the chamber. Cooling fluid flows upwardly in the tubular frame structure and discharges against the inner surface of the uppermost wall panel. The water flows down the panel until it is interrupted by a channel located beneath the uppermost panel. Water collects in the channel and overflows one side of the channel onto the next lower panel, thereby re-establishing the downward fluid flow. This panel and the others are also provided with channels whereby fluid flow is interrupted as it courses down each panel and the cooling water finally discharges at the bottom of the chamber.

This invention relates to exhaust receiving apparatus and more particularly to an evaporative type of exhaust apparatus for use with a basic oxygen furnace.

The making of steel in a basic oxygen furnace, by blowing oxygen onto or into a molten metal bath in a converter produces great quantities of hot efliuent, such as gases, fumes, and dust. The quantity of effluent discharged, for example, may be in the order of 175,000 cubic feet per minute, or more, and the temperature of efliuent gases may be 3,500 F., or higher. In the exhaust hood, the gases are cooled from about 3500 F. to a temperature of about 1200 F. Then, the gases flow through an evaporation chamber where they are further cooled, and humidified by means of water-emitting sprays arranged in suitable locations within the evaporation chamber.

The cooled gases expand in the evaporation chamber and lose most of their velocity, so that, when they emerge from the evaporation chamber, they are ready for further treatment.

Heretofore, the evaporation chamber was constructed of heavy internally water-cooled panels. Necessarily, such chambers presented a burdensome structural load of water and steel which required a massive support structure and foundation.

In the present invention, the evaporation chamber includes a generally hollow vessel having side walls and end closure means, with efliuent gas inlet and outlet openings strategically located in the side walls. One portion of the chamber is a flushing section having spaced apart vertical tubular conduit members forming a frame structure to which are removably attached a plurality of interconnected downwardly and inwardly sloping panels forming the eflluent retaining walls of the flushing section of the chamber.

Cooling fluid, such as water for example, is introduced into the frame structure, flows upwardly therein and is discharged therefrom via horizontal conduits adjacent the upper ends of the tubular frame members. The cooling fluid discharges onto the panels and flows downward as fluid films. The downward flow of the fluid films is successively interrupted by fluid collecting trays and reestablished by purposely overflowing the trays. Thus, the col- 3,345,057 Patented Oct. 3, 1967 lecting and redistributing of the films of fluid is carried out repeatedly as the fluid flows downward to the bottom of the flushing section. Thereafter the cooling fluid is suitably disposed of.

The efliuent gases enter the lower portion of the chamber, preferably adjacent the lower extremity of the flushing section, flow upward therein, and are discharged from the chamber adjacent the top thereof.

The lower end closure of the chamber of the present invention includes a hopper, in which dirt and other particulate matter, washed from the efiluent gases, collects and from which it is removed.

For a further understanding of the present invention and for advantages and features thereof, reference may be made to the following description taken in conjunction with the accompanying drawings forming a part of this application in which:

FIG. 1 is an elevational view of an evaporative exhaust receiving chamber in accordance with a preferred embodiment of the present invention;

FIG. 2 is a sectional view along line II1I of FIG. 1;

FIG. 3 is an elevational view, at an enlarged scale, of a portion of the flushing chamber of FIG. 1;

FIG. 4 is a sectional view along line IVIV of FIG. 3;

FIG. 5 is a sectional view along line VV of FIG. 3; and

FIG. 6 is a schematic view showing the chamber of FIG. 1 in a basic oxygen furnace system.

In the drawings, FIG. 1 illustrates an evaporative type exhaust receiving chamber, designated generally as 11, which includes a rectangular upper conduit portion 13, a rectangular lower conduit portion 15, and a trust-pyramidal hopper portion 17.

The upper conduit portion 13 includes four vertical planar plate members 19, which are connected together along their vertical longitudinal edges so as to form a gaseous conduit, which has a generally rectangular cross section. The upper end of the conduit 13 is open, but is preferably closed by an internally supported valve device 21 to which further reference will be made hereinafter.- In one of the vertical walls 10 adjacent the valve device 21, there is an effluent gas discharge conduit 23, having,

' preferably, a round cross section. This conduit 23 connects to a butterfly-type valve damper 25, which is also connected to a gaseous discharge conduit 27.

The lower conduit portion 15, or flashing section, connects integrally to the bottom of the upper conduit portion 13, and includes a frame structure 29 comprising spaced apart vertical corner and intermediary rectangular shaped conduits. Between the corner conduit 32, there is disposed a plurality of vertically arranged sloping panels 31, which form the walls of the lower conduit portion 15, as shown in FIGS. 3 and 4.

The vertical corner conduits 32 are generally square in cross section. In the embodiment illustrated in the drawings, they have dimensions of six inches by six inches with a wall thickness of of an inch. On each side of the lower conduit portion 15, between the corner conduits 32, there are, generally, two vertical intermediary conduits 33. In the embodiment illustrated, these intermediary conduits are rectangular in cross section, and have dimensions of four inches by six inches with a wall thickness of 7 of an inch.

The upper and lower extremities of the vertical conduits 32, 33 are closed by suitable closure members, such as plates 34, which may be welded to the walls of the conduits or fastened thereto in any suitable manner. Adjacent the upper extremity of each of the conduits 32, 33, there is a transversely and horizontally extending conduit 35. This conduit is connected conveniently to a nipple 37 projecting from one wall of the vertical conduits 32, 33; Such connection may be made .by means of any suitable coupling 39, for example, a Victaulic coupling. The horizontal conduit 35 is closed at the free end, which is disposed adjacent the next vertical conduit, by means of a plate 41, which may be welded to the conduit 35. The horizontal conduit 35 also has a longitudinal slot 43 in its lowermost wall, which is relatively narrow and which extends practically the length of the conduit 35, as shown in FIG. 4.

Each sloping panel 31 includes a flat plate 45 that is conveniently supported along its vertical edges by angle members 47. The angle members 47 are suitably secured to the plate 45, as by welding, and the panel 31 itself is secured in place, between adjacent vertical conduits 32, 33, by means of nuts threaded onto studs 48 fixed to the walls of the conduits 32, 33. The angle members 47, have slots 49 along one edge to receive the studs 48. Thus, the panels may be readily installed and removed from within the conduit 13, whenever necessary. Each panel 31 is disposed in a downwardly and inwardly sloping manner, about as shown in FIG. 4, and the lower edge of the uppermost panel is located about at the level of the top edge of the next adjacent lower panel. A generally horizontal closing and sealing plate 51 is fastened, as by welding, to each panel adjacent its lower edge, and extends over the upper horizontal edge of the next lower panel, as shown in FIG. 4. The horizontal closure plate 51, however, is not secured to the top edge of the next adjacent lower panel, but merely rests thereon. Therefore, the horizontal closure plate forms an efliuent seal between adjacent vertical panels, but still the panel to which it is fixed may be removed readily whenever necessary.

The panels 31 are disposed downwardly and inwardly, as mentioned previously, so that water, flowing in the horizontal conduit 35, discharges via the longitudinal slot 43 onto the inner vertical surface of the panels and flows downwardly as a film of water. There is located, adjacent the top of each panel (except the topmost panels) a channel-shaped redistribution tray 53. A redistribution tray 53 extends transversely across each panel 31 and is closed appropriately at the ends so that it may hold and retain water. The tray 53 is set out from the surface of the panel to which it is attached, by means of suitable spacer pieces 57. Preferably, the redistribution tray 53 is disposed substantially perpendicular to the surface of the respective panel to which it is attached, as may be noticed by referring to FIG. 4, and one or more spaces are formed between the tray and the panel.

Below each tray 53, it is convenient to provide a plurality of spaced apart tray supporting brackets 59, in each of which, there is an aperture 61, for a purpose to be disclosed hereinafter. These brackets may be secured to both the tray 53 and the panel plate 45 by welding, or in any other suitable manner.

Adjacent the lower edge of the lowermost panel 31, there is provided, as shown in FIGS. 1 and 2, a flushing water supply conduit 63 which intercommunicates the vertical corner conduits 32 and the intermediary conduits 33, respectively. It will be noted from FIGS. 2 and 6, that, in one side of the chamber 11 and, particularly, in the lower or flushing section 15, there is an opening 65. The upper end of a basic oxygen furnace hood structure 67, such as shown and described in the aforementioned co-pending application, is appropriately connected to the chamber 11 at the opening 65. As mentioned previously, the effluent discharged from a basic oxygen furnace 70 flows therefrom via the hood structure 67 into the evaporative chamber 11 of the present invention. The eflluent gases enter the chamber 11 at the opening 65 and flow generally upwards throughout the chamber 11.

The uppermost end portion of the lower conduit or flushing section 15 is conveniently connected, as shown in FIG. 4, to the lower end portion of the upper conduit section 13. Such connection is preferably effected by means of a sliding joint, which includes the peripheral angle 69 disposed so as to slidingly contact the walls 19 of the upper section.

The upper end portions of the tubular conduits 32, 33 are connected together and conveniently fixed in spaced apart relation by a channel member 71 that is bolted, as at 73, to a plate 75, which is secured to the tubular members in any suitable manner. Between the tubular conduits 32, 33 at the upper ends thereof, there is a vertically depending plate 77, which is appropriately knuckled, as at 79, so that the lower portion 81 is directed downwardly and outwardly toward the topmost panel 31. Appropriately, this lower portion 81 forms a part of a gas seal, and it also serves to deflect the water, issuing from the horizontal tubular member 35 toward the panel 31, so that it forms a water film on the plate 45. The vertically depending plate 77 is conveniently secured to angles 83 fixed to the vertical tubular members 32, 33, by means of bolts 85, as shown in FIG. 4.

The sliding joint between an angle member 69 and the walls 19, is protected from contamination by a pair of other angles 87, 89 which may be welded together, as shown in FIG. 4. The angle 89 may be secured to the walls 19, as shown, by means of bolts 91, or any other appropriate manner. The angles 87, 89 are generally disposed so that one leg of angle 87 is spaced from, and parallel to, the upstanding leg of angle 69. The depending leg of angle 87, therefore, overlaps the vertical leg of angle 69, and, thus, provides a seal for the sliding joint.

The hopper conduit 17, as shown in FIG. 1, connects integrally to the lower end of the flushing section 15. The hopper conduit 17 includes a generally straight portion 93 and a frusto-pyramidal portion 95, secured thereto as by bolts 97. The walls of the frusto-pyramidal portion 95 are appropriately stitlened by laterally extending and vertically spaced apart angle members 99. The lower end of the frusto-pyramidal portion 95 is connected by means of a pair of mating bolted flanges 101, to a conventional Waste conduit 103.

The evaporation chamber 11 is conveniently supported at various vertical levels by appropriate structure, such as the encompassing angle structure 105, which is conveniently connected to adjacent supporting floor members 107 and to adjacent beams 109, as shown in FIGS. 1 and 2. The chamber 11 may be supported vertically by structure, such as the horizontal beams and columns 111.

At convenient vertical levels of the chamber 11, it is desirable to provide walkways and railings 113 for the purpose of servicing the chamber. At other vertical levels, it is desirable to provide encompassing fluid conduits 115 which supply flushing water to the banks of internal spray nozzles 117. Such an arrangement of walkways and conduits is suggested in FIG. 1.

When the basic oxygen furnace 70 is operating, the hot eflluent gases, as mentioned previously, enter the evaporation chamber 11 via the hood 67 at the opening 65. The gases are then at a temperature of about 1200 F. The dry, hot effluent gases, however, contain dirt and other foreign matter which must be removed and the gases must be cooled before receiving further treatment. The efiluent gases, coursing upward through the chamber 11, encounter water from the spray nozzles 117 which cools the gases and the wetted dirt particles fall downward into the hopper portion 17, and are removed therefrom via the waste conduit 103.

Water is circulated in the supply conduit 63, and is forced by pump means (not shown) upwards in the corner and intermediary conduits 32, 33, respectively. The water then flows in the horizontal conduits 35 and emerges therefrom via the longitudinal slots 43, as a film of water. The film of water, impinging against both the uppermost panel plate 31 and the lower plate portion 81, flows downward over the surface of the uppermost panel, in a first zone, designated A in FIG. 4. The water is collected in the first redistribution trays 53 until it reaches a level therein where, due to the upwardly inclined position of the tray, the water overflows the rear or outer edge of the tray. The overflowing water then forms other films of water on the panels in the zone designated B. These new films of water, in like manner, flow down the inner surface of the panels throughout zone B, and collect in the redistribution trays beneath these panels. The water is collected in these second trays until it reaches a level where it overflows the rear edges of the trays and forms other films on the panels in a Zone designated C. Thus, the cooling 'water flows intermittently downward over the panels until it reaches the lowermost level of the flushing section 15, where it is collected in a lowermost tray formed by the angle 105 encircling the chamber 11. Thereafter, the cooling water may be disposed of in any suitable manner.

In the present invention, the panels 31 are made in a convenient size for ready and easy replacement. From time to time such panels may have to be removed and replaced. It is to be noted, that each panel may be removed by simply loosening the nuts on the stubs 4S. Thereafter the panel may be removed by connecting and attaching lifting mechanism, such as a shackle bolt, to the holes '61 in the brackets 59 andthen sliding the panel inwardly and removing it upwardly and out through the top of the chamber 11. The panels of the present invention are simpler and less expensive, and are significantly lighter in weight than conventional water jacket type panels used heretofore.

In the preferred embodiment of the invention, shown and described herein, the chamber 11 has a rectangular cross section and the vertical corner and intermediary conduit members 32, 33 are generally rectangular. It should be understood, however, that the present invention is not limited to the embodiment shown and described. The chamber and the conduits may, if preferred, be cylindrical, oval, square, or they may have any other suitable shape and arrangement.

In the present invention the tubular frame structure supports the weight of panels 31 and carries the entire supply of flushing water to the top of the flushing section of the chamber. Moreover, attachment of the panels to the frame structure is accomplished in a simple and convenient manner whereby the panels may be readily and easily removed whenever necessary.

In the present invention, .the tubular frame structure replaces the conventional Water headers and piping system for supplying water to the usual banks of spray nozzles. Such headers and piping system are expensive and costly to maintain. A feature of the present invention is that the cooling fluid which in most applications will be water, performs several functions. First, the fluid courses the tubular frame conduits and cools them while it is being conducted upwardly for other purposes. Second, the films of cooling fluid coursing down the panel interior surfaces condition the efliuent gas by being evaporated into the gas stream. Third, the films of fluid cool the panel surfaces since the fluid is constantly being evaporated into the gases as they flow through the chamber.

The foregoing presents a novel exhaust receiving apparatus or evaporation chamber for use with a basic oxygen furnace. Such a chamber is ligher in weight, easier to construct and maintain, and the gas cooling and conditioning is more effective and efficient.

We claim:

1. In an evaporative chamber for treating the effluent from a basic oxygen furnace, the improvement comprismg:

(a) a frame including spaced apart substantially vertical conduit members;

(b) means for supplying cooling fluid to said conduit members from a source of cooling fluid;

(c) downwardly and inwardly sloping panels disposed between and secured to adjacent vertical conduit members, said panels being interconnected so as to form the walls of said chamber;

(d) a horizontal conduit communicating with each vertical conduit adjacent the upper end thereof and having a longitudinally extending aperture in its wall whereby cooling fluid flowing in said horizontal conduit discharges therefrom onto an adjacent panel and forms a fluid film thereon; and

(e) fluid receptive means mounted to said panels Whereby said cooling fluid coursing down said panels is collected in said receptive means and redistributed therefrom over the surface of an adjacent lower panel.

2.. An evaporation chamber for treating the eifluent from a basic oxygen furnace comprising:

(a) a frame comprising spaced apart substantially vertical conduit members adapted to conduct cooling fluid;

(b) means for supplying cooling fluid to said conduit members from a source of cooling fluid;

(c) downwardly and inwardly sloping panels disposed between and secured to adjacent vertical conduit members, said panels being interconnected so as to form efiluent retaining walls of said chamber;

(d) means for variably closing the upper end of said chamber;

(e) horizontal conduits communicating with said vertical conduits adjacent the upper ends thereof each having an aperture in its wall whereby cooling fluid flowing in said horizontal conduit discharges therefrom onto an adjacent panel;

(f) fluid receptive means mounted to said panels whereby said cooling fluid coursing down said panels is collected;

(g) means to re-establish the downward flow of fluid over the surface of adjacent lower panels;

(h) means to introduce said effiuent into said chamber adjacent the lower end thereof;

(i) means to discharge said effluent adjacent the other end of said chamber;

(j) means to inject fluid into said chamber whereby said eflluent is cooled and particulate matter in said effluent is separated therefrom; and

(k) means connected to the lower end of the walls of said chamber adapted to collect and discharge the particulate matter removed from said eflluent.

3. An evaporation chamber for treating the efliuent from a basic oxygen furnace comprising:

(a) a plurality of vertically adjacent panels arranged in spaced apart relation forming a part of the side walls of said chamber;

(b) a plurality of walls, each one connecting a pair of adjacent side wall panels forming the other part of said side walls;

(c) a frame supporting said panels comprised of spaced apart substantially vertical fluid conductive members;

(d) means for injecting cooling fluid into said frame;

and

(e) a horizontal conduit communicating with each said vertical conduit adjacent the upper end thereof and having apertures along its length whereby cooling fluid flows from said horizontal conduit onto the surface of said panels and courses down said panels.

4. The invention of claim 3 wherein:

(a) the downward fluid flow over each side wall and is within said chamber, said flow being interrupted at least once and re-established at least once.

5. The invention of claim 3 wherein:

(a) separate means is provided to inject cooling fluid into said chamber to contact and cool said efiiuent.

6. A basic oxygen furnace system comprising:

(a) a basic oxygen furnace;

(b) a hood adapted to conduct eflluent from said furnace; and

(c) an evaporation chamber for treating said effluent and communicating with said hood, said chamber comprising a frame comprising spaced apart substantially vertical conduit members adapted to conduct cooling fluid, means for supplying cooling fluid to said conduit members from a source of cooling fluid, downwardly and inwardly sloping panels disposed between and secured to adjacent vertical conduit members, said panels being interconnected so as to form eflluent retaining walls of said chamber, means for variably closing the upper end of said chamber, horizontal conduits communicating with said vertical conduits adjacent the upper ends thereof each having an aperture in its wall whereby cooling fluid flowing in said horizontal conduit discharges therefrom onto an adjacent panel, fluid receptive means mounted to said panels whereby said cooling fluid coursing down said panels is collected, means to re-establish the downward flow of fluid over the surface of adjacent lower panels, means to introduce said effluent into said chamber adjacent the lower end thereof, means to discharge said eflluent adjacent the other end of said chamber, means to inject fluid into said chamber whereby said effluent is cooled and particulate matter in said effluent is separated therefrom, and means connected to the lower end of the walls of said chamber adapted to collect and discharge the particulate matter removed from said eflluent.

7. The invention of claim 6 wherein:

(a) said fluid courses down the inner surfaces of the wall panels of said chamber.

8. In combination with a basic oxygen furnace and a hood adapted to conduct the eflluent discharged by said furnace, an evaporation chamber comprising:

(a) a frame comprising spaced apart substantially vertical conduit members adapted to conduct cooling fluid, means for supplying cooling fluid to said conduit members from a source of cooling fluid, downwardly and inwardly sloping panels disposed between and secured to adjacent vertical conduit members, said panels being interconnected so as to form eflluent retaining walls of said chamber, means for variably closing the upper end of said chamber, horizontal conduits communicating with said vertical conduits adjacent the upper ends thereof each having an aperture in its wall whereby cooling fluid flowing in said horizontal conduit discharges therefrom onto an adjacent panel, fluid receptive means mounted to said panels whereby said cooling fluid coursing down said panels is collected, means to re-establish the downward flow of fluid over the surface of adjacent lower panels, means to introduce said effluent into said chamber adjacent the lower end thereof, means to discharge said effluent adjacent the other end of said chamber, means to inject fluid into said chamber whereby said efiluent is cooled and particulate matter in said eflluent is separated therefrom, and means connected to the lower end of the walls of said chamber adapted to collect and discharge the particulate matter removed from said effluent.

9. An evaporation chamber for treating the effluent from a metallurgical furnace comprising:

(a) a tubular support frame adapted for conducting cooling fluid therewithin;

(b) a plurality of panels that are vertically arranged in substantially spaced apart parallel relation and that are connected to said tubular frame, forming the effluent retaining walls of said chamber;

(0) means connecting said vertically adjacent panels whereby said walls retain said efiluent;

(d) means for closing the ends of said eflluent chamber;

(e) means for introducing the eflluent gases into said chamber adjacent one end thereof;

(f) means for discharging the efiluent gases adjacent the other end of said chamber;

(g) means for injecting cooling fluid into said tubular frame;

(h) means for ejecting said fluid from said frame whereby said fluid impinges upon and flows downwardly on said Walls and cools the same; and

(i) fluid receptive means mounted to said walls whereby the fluid coursing down said walls is collected and thereafter redistributed over the surface of said walls.

References Cited UNITED STATES PATENTS 2,155,853 4/1939 Anthony, 2,944,966 7/1960 Eickmeyer 26l112 X 3,212,235 10/1965 Markant.

J. SPENCER OVERHOLSER, Primary Examiner.

E. MAR, Assistant Examiner. 

1. IN AN EVAPORATIVE CHAMBER FOR TREATING THE EFFLUENT FROM A BASIC OXYGEN FURNACE, THE IMPROVEMENT COMPRISING: (A) A FRAME INCLUDING SPACED APART SUBSTANTIALLY VERTICAL CONDUIT MEMBERS; (B) MEANS FOR SUPPLYING COOLING FLUID TO SAID CONDUIT MEMBERS FROM A SOURCE OF COOLING FLUID; (C) DOWNWARDLY AND INWARDLY SLOPING PANELS DISPOSED BETWEEN AND SECURED TO ADJACENT VERTICAL CONDUIT MEMBERS, SAID PANELS BEING INTERCONNECTED SO AS TO FORM THE WALLS OF SAID CHAMBER; (D) A HORIZONTAL CONDUIT COMMUNICATING WITH EACH VERTICAL CONDUIT ADJACENT THE UPPER END THEREOF AND HAVING A LONGITUDIALLY EXTENDING APERTURE IN ITS WALL WHEREBY COOLING FLUID FLOWING IN SAID HORIZONTAL CONDUIT DISCHARGES THEREFROM ONTO AN ADJACENT PANEL AND FORMS A FLUID THEREON; AND (E) FLUID RECEPTIVE MEANS MOUNTED TO SAID PANELS WHERE- 